Navigation and inspection system

ABSTRACT

A method of detecting a changed condition within a geographical space from a moving vehicle. Images of that geographic space are memorialized in conjunction with GPS coordinates together with its GPS coordinates. The same geographic space is traversed from the moving vehicle while accessing the route&#39;s GPS coordinates. The memorialized images are played back by coordinating the GPS data on a memorialized images with that of the traversed geographic space such that the memorialized images are viewed simultaneously with the geographic space being traversed. An observer traveling within the moving vehicle can compare the memorialized images with those being traversed in order to identify changed conditions.

TECHNICAL FIELD

Video is typically recorded by time, for example, 30 frames per second.By selecting which frames to record and or use according to GPS of thecamera position or according to distance traveled, a new database iscreated. This video or sequential image database incorporatesgeographically referenced images that are spatially related rather thantime related. By the selection of a distance between frames to identifywhich frames are to be acquired rather than time, a dramatically smallerdatabase results that is able to be searched more easily. This providesfor a dramatically reduced size in the database and is a technique ofdata compression. Specific frames or data can be more easily retrievedby geographic position that can be determined by global positionsatellites, inertial systems or other electro mechanical sensors.Traditionally, forward looking video views have not been recorded bydistance traveled or relative geographic position. They are separated bytime rather than distance. The present invention involves a navigationand inspection system having particular utility for a more precise formof vehicle navigation or inspection of nearby objects. For example itcould be used if one desires to rapidly perform an inspection of aroadway looking to identify a new crack or hole in the pavement of aroadway, tunnels or bridges or roadside encroachment due to vegetationor land movements. In addition, changes in nearby objects such as powerlines, building facades, parked cars can be identified. Otherapplications include enhanced nighttime driving to provide a daytimeimage of the current position and heading, a more precise navigation toconform a vehicle to precisely navigate over a previously identifiedpath and the enhancement of current imagery with previously acquireddata or imagery such as objects recorded during daytime fused with thenight time imagery. It is also possible to use the invention to identifya current GPS position by selecting the closest matching frame in thedatabase with a known GPS co-ordinate that was previously acquired.

BACKGROUND OF THE INVENTION

In the past, topography including roadways have been geomapped,principally by aircraft traveling above the to be mapped region from topdown views. However, in light of wobbling aerial camera platforms, lookangle limitations and lens distortions converting an aerial map of aregion to a surface based operator view, prior geomapping techniqueshave proven complex. Additional complications come from the mosaicingtechniques that are required to integrate frames along the route beingtraveled into a searchable database. Further, for a vehicle operator toidentify changes between geomapped imagery, it has been determined to becognitively most helpful to provide a split screen or some other type ofparallel tracking display of a geomapped route to the route currentlybeing navigated to enable rapid comparisons to be made between currentconditions and those which act as a standard upon which future actionsor inspections would be based.

The hardware requires the simultaneous or near simultaneous display ofthe current image and the geographically referenced database image.

It is thus an object of the present invention to provide a ready meansof providing a vehicle operator sufficient information to enable theoperator to identify surface changes or nearby feature changes oridentify a specific changes in nearby objects or their relativepositions.

It is yet a further object of the present invention to provide means ofalerting the driver to upcoming road conditions by looking forward inthe database to what is over a hill or around a bend.

It is yet a further objective of the present invention to integrateinformation from the inspection of roadways or other roadside conditionsin a format which highlights such conditions and hazards and whichpresents them to a vehicle operator in a timely fashion to provide theoperator the opportunity to take effective remedial action.

It is a further object to provide daytime views given a GPS location andheading.

It is a further object to present to a driver a behind the vehicle viewbased on previous views with the vehicle perimeter represented on screenso that the current relationship of the wheels to hazards can be viewedand is approximately accurate to the current vehicle position.

It is further object to provide a means to reduce the number of framesand size of a database by recording imagery by distance separationrather than time. This was usually done by recording all frames in asequence done at 30 frames per second and tagging the GPS position onall thirty frames. Although the invention can be practiced with all 30frames, the preferred embodiment is to record a frame after the camerahas moved a specified distance to reduce the bandwidth and storagecapacity required.

It is further object to utilize other forms of imagery or data such asladar, radar, sonar, magnetics, multi-spectral, audio, computerrenderings from depth maps or wireframes or other forms of data such assound that can be discretely acquired by geoposition. These alternativesources of data can be mixed such as thermal with daytime video,magnetics with video, multi-spectral with rendered imagery.

It is further object to identify a current GPS position by selecting theclosest matching frame in the database with a known GPS co-ordinate thatwas previously acquired.

These and further objects will be readily apparent when considering thefollowing disclosure.

SUMMARY OF THE INVENTION

The present invention involves a method of detecting a changed conditionwithin a geographic space from a moving vehicle. The method comprisescapturing and memorializing images of the geographic space inconjunction with GPS/geographic coordinates associated with saidgeographical space. The geographical space is traversed from said movingvehicle while accessing GPS or other geographic coordinates. Thememorialized images are accessed and played back by coordinatinggeographic coordinate data on said memorialized images with thetraversing of said geographic space such that said memorialized imagesbeing viewed are of the same geographical space being traversed, (i.e.the position of the camera now and in the past are within the samegeographic coordinates and headings +/− some tolerance). Bothmemorialized images and the images of the traversed geographic space arepresented to an observer enabling the observer to make a directcomparison of the memorialized images and images of the geographic spacebeing traversed to the observer. Ideally, the memorialized images arecreated by employing a video camera which can also be used to presentthe geographic space being traversed. Alternatively, other imagecapturing devices can be employed such as infrared cameras, sonar, orsensor data such as magnetic or sound data that can be graphicallyrepresented on a screen. To present the most direct comparison, thecamera presenting the traversed images from the moving vehicle should beplaced in approximately the same location and heading as that of thecamera employed to capture the memorialized images with a similar fieldof view. Fields of view can be better matched optically or by electronicscaling. Image stabilization techniques can also be used to improve therelative registration between images. Both images can be presented upona screen, such as a split screen in which the traversed images arepresented above and the memorialized images are presented below.Alternative displays such as sequential presentations, alternating,super-imposition or keying and matting techniques can also be used. ByGPS coordination, the images of the same geography are presented to anobserver simultaneously enabling the observer to quickly and intuitivelyrecognize any changed conditions in the roadway. Further, although thememorialized images and traversed images can be taken and capturedduring the daytime to provide a meaningful comparison with daylightviews, the present invention can also be employed to enhance nightdriving by comparing memorialized images taken during the day whenvisibility is relatively good and playing back those images on asuitable split screen with real time images taken at night or duringinclement weather. The display of the recorded daylight single viewselected by current GPS position presents valuable information that maynot be visible in the current situation. The simultaneous display of thecurrent and previous condition would not be required. Sometimes ininclement weather or GPS obstruction, the current GPS could be lost. Bycomparison of current imagery to the database imagery, a current GPSposition could be selected by the closest image match to a specificframe in the database.

Because a driver may not have a direct view of his wheels inrelationship to a ravine or cliff or other hazard, an accidental rollover can occur. By using a gps based offset that is some distance behinda vehicle, a navigation view can be presented to a driver. The outlineperimeter of the vehicle including its wheels can be superimposed overthe collected imagery. A view can be displayed that includes a view ofthe road and vehicle that appears to be from a camera behind thevehicle. This is accomplished by using a GPS position that isapproximately 20 feet from the current position to determine the videoframe best associated with the current position.

By placing a dot (Breadcrumb) in the proper location on a carteseancoordinate system on the display one can create a map that representsthe memorialized data. Breadcrumb marks on a top down map for each framecan then be composited to provide accurate maps of the driven area.These maps may be overlayed onto standard reference maps which may beimported into the system. This provides a graphic interface that can beused to present the view of the route that at any specific speedselected.

Change detection is enhanced at night by the use of auxiliary lightingin the visible or infrared wavebands. At night, using auxiliary lightingplaced lower than the camera, exaggerates elongated shadows to producean enhanced shadow effect to highlight changes. This auxiliary lightingcan be constant or pulsed to co-ordinate with the GPS capture of theframe after a specific distance is traveled. The lighting can be in thevisible and/or non-visible range.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic block diagram of the essential componentsnecessary in carrying out the present invention.

FIG. 2 depicts a typical split screen presentation of data which wouldbe presented to a vehicle operator in practicing the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Others, in the past, have taught methods of recording images andassociating them with GPS or geographic coordinate data to provideplayback that was position, rather than time dependent. For example,reference is made to U.S. Pat. No. 6,741,790, the disclosure of which isincorporated by reference. The '790 patent teaches a system includinghardware and software which are configurable and operable in threemodes, namely, recording mode, indexing mode and playback mode. In therecording mode, the hardware employed therein is connected to a GPSreceiver and video recording device and permits GPS data to be recordedon the same recording medium that images are recorded on using the videorecording device. As a result, a particular geographic locationassociated with particular images can be directly referenced by GPSdata. After recording the images, the hardware device is connected to acomputer having the appropriately installed software causing the GPSdata to be transferred from the recording medium to the computer as therecorded images are played. During this indexing step, the computerdraws a map showing all of the GPS reference locations recorded on therecording medium. Each map location represents a location where imageswere recorded with GPS data. Once the indexing mode is completed, thesystem disclosed in the '790 patent can be used to play back the imagesso recorded, in accordance with the selection of a location on the map.During this step, called the playback mode, a marker may be selected onthe computer generated index map and the system will cause the videorecording device to play back the images that were recorded at theselected location. The '790 patent also teaches recorded images beingtransferred to some other media such as a CD ROM or hard disk causingthe computer to play back the images that were recorded at that selectedlocation. However, no one to applicant's knowledge has adapted thistechnology for the purpose presented herein. For example, the presentinvention can in its preferred embodiment, use GPS to determine when apicture is recorded to reduce the number of frames in memory and whichimage to be called during playback. Although all frames can be recorded,it is best to only record those separated at a deliberately setdistance. Thus the camera frame rate is dependent on the velocity of thecamera. This can also increase the required camera frequency of recordedimagery past 30 frames per second for higher travel velocities throughthe use of a GPS triggered camera.

In addition, U.S. Pat. No. 6,895,126 teaches a system and method forsynthesizing images of a locale to generate a composite image thatprovides a panoramic view of the locale. The '126 patent disclosesemploying a video camera moving along a street recording images ofobjects along the street. The GPS receiver and inertial navigationsystem provide the position of the camera as the images are beingrecorded. The images are indexed with the positioned data provided bythe GPS receiver and inertial navigation system. According to one aspectof the '126 invention, an image recording device moves along a pathrecording images of objects along the path. As noted, the GPS receiverand/or inertial navigation system provides position information of theimage recording device as the images are being acquired. The image andposition information are provided to a computer to associate each imagewith the position information. As such, it is known in the prior art toassociate GPS coordinates with recorded image data for later playback.The disclosure of U.S. Pat. No. 6,895,126 is incorporated herein byreference.

As a first embodiment, the present invention involves a detection systemutilizing human intervention to detect changes in a scene by displayingvideo of a topography such as a roadway along with imagery captured froma previous trip. During acquisition, the system captures images from alive video feed and “meta-tags” them with additional informationincluding the location and orientation of a specific viewpoint.Important “meta tag” information would include, for example, directionof travel and GPS coordinates and or elevation. These ‘meta tags’ arethen associated with specific frames of the previously taken videoimage. During playback, the system utilizes current location andorientation through GPS data acquisition to recall imagery previouslycaptured from approximately the same location and orientation. Ideally,the two images are displayed on a single screen above and below oneanother. In some applications, such as driving at night, only the storedview will be displayed. GPS data acquisition provides the coordinatesthat determine the closest “stored views” to the vehicle's currentlocation. This can also be done using various “closest matching frame”software. This system then selects corresponding views from a databaseto produce the nearly exact view that a vehicle operator, such as asoldier, is observing in real time in the vehicle. Compensation of thedatabase view can be made for variances in camera Field of View, speed,distance to the center of the road and X and Y variances from theposition on the road from which the reference data was taken. Thesecorrections can be determined from physical sensors on the cameraplatform such as inclinometers and accelerometers or from calculationsderived from the sequence of images. The information is presented in anenhanced format for easy comparison to the observer to enable a vehicleoperator to make real time decisions about a road hazard.

As a preferred embodiment, the image can be deliberately distorted byincreasing the horizontal width to minimize the relative vertical motionor an unusual horizontal aspect ratio can be used to provide the viewerwith less vertical distance between before and after pictures thusminimizing eye movement. This can be done, for example, by cropping theimage reducing the area above the horizon in carrying out this function,reference is made to FIG. 1 showing system 10 as constituting oneversion of the present invention. Specifically, system 10 includes acomputer 11 which is fed information from elements 12 and 13. Element 12is an image source generator such as a visual or thermal camera which isemployed in conjunction with GPS device 13 to “meta tag” framesgenerated from camera 12 and applied to computer 11 for storage. Theimage developed through this established reference would appear in thebottom portion of split screen 14 in image area 16 as discussed furtherin reference to FIG. 2. When traveling over the same route upon whichthe image projected in field 16 is played back, camera 12 againgenerates an image and the image thus created is coordinated with GPSdevice 13 and “meta tagged” with GPS device 13 and is again introducedto computer 11 which generates a real time image in upper frame 15 ofdisplay 14. Because the stored image and current image are both “metatagged” with GPS coordinates, playback of a specific scene inconjunction with a current route being undertaken are coordinated fordirected comparison.

The utility of the present invention can be appreciated in reference toFIG. 2. As noted, the split display screen 14 displays roadway 17 andits surrounding topography. The image displayed in lower half 16 ofdisplay 14 is an image taken of a roadway at an earlier date and time.Roadway 17 and its surrounding topography displayed in upper screenportion 15 shows a similar portion of the roadway, each view expandedhorizontally to enhance visual recognition of horizontally presentedobjects such as objects 19 sitting on the outside of shoulder 18. Imagesgenerated are ideally taken with a telephoto lens in order to provideadequate time for a vehicle operator to take action in the event thatthe operator wishing to investigate the nature of new objects 19 in theevent they represent potential hazards applied to the roadway by such asfallen trees or earthquake created obstacles.

The image generated in row or frame 16, that is, that showing a previousdepiction of a roadway and surrounding topography can be acquired from amultitude of sources such as previous vehicle runs. Such information canbe electronically submitted to a central server which can be accessed byremote displays.

The main hardware components involved are a laptop PC, server or DVDburning system, small GPS receiver and a video camera, or other sensorproviding 2 or more dimensions of data. The principle softwarecomponents include simultaneous video/data capture and playback, thecapturing of location and orientation information from sensors on USBand/or serial ports, utilizing “meta tags” to associate the differentdata sets, storing the data in a format that can be shared or combinedwith other geo-spatial information, techniques for annotating the storedimagery to locate features such as potentially dangerous areas along theroute, an interface to interact with the data and a way to share thedata with others who will travel the same route at a later time.

An advanced functionality under consideration includes the ability totrack or predict viewpoint motion in cases of a limited GPS signal. Thiscan be done by inertial sensors or a technique of identifying theclosest frame selected from a sequence of frames with known GPSpositions.

Other identified significant applications include training and dispatchor route planning. Driving simulators would be improved from the currentcartoon like images to real video.

Nighttime operations with IR and thermal sensors and alternative sourcessuch as magnetic maps or ladar can also be utilized.

A simple training device is a DVD of the recorded route that is playedon a DVD player.

As to simultaneous video capture and playback, live video will bedisplayed with previously captured imagery in an over/under fashion ontwo parts of the screen to facilitate change detection comparison. Tocreate a random accessible database (as opposed to an MPEG video stream)a JPEG storage architecture can be used. The capture of the still imageswill be based upon parameters including the distance traveled andheading.

Turning to capturing location and orientation information from sensorson USB and/or serial ports, the video, GPS and heading sensors willinterface to the system through the USB or serial ports and or videoframe grabbers. A Panasonic® Toughbook® PC, for example, will hostsoftware to pull and retrieve information from the sensors on theseports. “Meta tags” are used to associate the different data sets. “Metatags” are a way to associate different data sets without requiringexplicit relationships to be exercised. This system will utilize “metatags” to relate features including the location and orientation of aviewpoint with its corresponding image. Time of day and unusualoccurrences can also be “meta tagged”. It is part of the invention toinclude the heading information in the “meta tag” so that the directionof travel going north or south can determine the proper image. Otherdata can be elevation and annotations of unusual occurrences.Predetermined commands can also be embedded in the data and are onlydisplayed in proximity to annoted geo-referenced “meta tagged” markers.

Data is stored in a format that can be shared or combined with othergeo-spatial information. The system will store the data in a format thatcan be used with other geospatial products such as those routinely usedin the geo mapping industry with layers for features such as elevations,names of streets, rivers wireframes or shape files such as those fromESRI.

The present invention provides a way to share the data with others whowill travel the same route at a later time. A client server model (datafile management server) can be used to store and share the data amongstpatrons. Data can be transferred between the client and server usingnetworks or DVDs or other data media. Capture laptops will have DVDrecording systems that will be able to publish DVDs for distribution tothe server or directly to other users. The system design and topologywill depend on what type of network infrastructure and bandwidth isavailable in a given community. The server will have a top down map viewof the acquired vehicle paths. Any point on a path can be mouse clickedto provide the specific in vehicle view.

As an example, a PC or laptop computers could be employed. Webcam andvideo sources can be used including images having a 9-degree field ofview for small objects seen at 100 meters or a wider field of view forcurved streets or urban environments. It is believed that the mind'sability to register non-conforming images is vastly underestimated. Bypresenting images on a single split screen one on top of the otherenables a viewer to immediately recognize irregularities and often timesone can determine the relevance of such differences while ignoringdifferent camera positions, fields of view, contrast, shadows and colordifferences between the images. Other techniques such as alternating theframes at various rates, super imposition, matting of features, orfusing of the imagery can also be used.

It is contemplated that a previously recorded view of a roadwayincluding surrounding topography could be projected and compared to areal time view of the same region projected on the windshield of amoving vehicle as well. This may be useful for nighttime driving.However, a preferred embodiment is to provide a split screen wherebypreviously recorded video is compared with live video taken from avehicle moving along a roadside. By providing one scene over anothercoordinated through the use of GPS coordinates “meta tagged” within acomputing system, the vehicle operator can most readily detectdifferences between the “before and now” videos. The current embodimentrelies upon commercial off-the-shelf GPS technology to retrieve apreviously recorded reference view from a database that is nearlyidentical to the current “live” vehicle-mounted camera view. Again,ideally, both video views are simultaneously presented on a singledisplay for visual comparison. Such a technique presents the two viewsin a manner that significantly augments and enhances the operator'snatural ability to detect a “change” of new surface object.Semi-automated change detection software may also be employed tohighlight disparities between the views. Such software is availablecommercially. In another variation, the rapid presentation between thebefore and after pictures creates an animation with the changed parts ofthe picture appearing to blink on and off.

In contemplating software applications, it is noted that single framesare available as geo-referenced data frames, but are used as top downmap views. Several commercially available software packages are videobased, but they generally use an MPEG compression protocol noting thatonly the initial frame could be geo-referenced and easily selectablewithout excessive decoding. MPEG compression further requires additionalprocessing bandwidth and the utilization, again, of key frames. The useof key frames presents significant problems for accessing a specificframe within two points and would require significant databasemanagement tools. It was found that JPEG compression could be moreviable by eliminating the need for key frame reference and complex dataaccessing and data management tools.

The present invention has been described as using video or thermalcameras to produce images. Different combinations can also be used forthe before and current situation data sets such as a daylight videocolor camera for the acquisition and a black and white thermal sensorfor a current night time image. In using thermal cameras, the presentinvention can be utilized at night while providing the necessary imagerecognition and image differentiation presentations for carrying out thepresent invention from the daytime image. Imagery can also be computergenerated from wire frame and/or texture maps. Magnetic profiles,multi-spectral imagery, radar, sonar or ladar are also viable for use inpracticing the present invention. Road like video, thermal HD, or lowlight NTSC video could also be employed as viable video sources notingthat the key in practicing the present invention is the production ofgeo-referenced discreet raster based imagery.

It is contemplated that, as an embodiment, the data produced fromgeo-mapping a specific route can be stored in a format that can beshared or combined with other geospatial information. There have beengeo-spatial extensions created for databases such as Oracle® sourcedsoftware or ESRI to make database access easier. The formats forexchanging information have been developed by organizations such as thatavailable online at www.opengis.org. It is noted that the InternationalStandard ISO 19136, the Geographic Information-Geography Markup Language(GML) contains instructions to store, combine and/or relate informationwith other geo-spatially reference data sets. There is a featuresub-type that has a coverage function over a spatial domain such aspopulation and density, and an observation is considered to be somethinglike a photo or measurement, noted with a time and possible othergeneral values for the observation. The present invention intends toutilize the observation features as a template for data storage.Notations such as cautions can also be made that are referenced andstored with time captured and GPS location camera orientation noted asreferences. Noting that Open GIS specification includes portrayals ofgeographic information, map-type interfaces can be employed usingsymbols on suitable maps that display points of observation and thuswill allow others to retrieve and display information interfaces createdin the practice of the present invention.

Although the preferred embodiment in practicing the present inventioncontemplates a comparison between archival video taken from a vehicleand comparing it to real time video taken in substantially the sameorientation, that is, from a moving vehicle, alternative video sourcessuch as forward looking aerial and down looking reconnaissance can beemployed herein. Skewed transformation and cropping can be employed tocreate a forward-looking aerial view into something akin to a view takenfrom a land-based vehicle. In doing so, aerial imagery must be employedin conjunction with processing not needed for land based image capture.For example, ego vectors on the aerial camera platform such as pitch,roll and yaw must be accounted for. Alternatively, the vehicle view canbe transformed to look like a top down view which could then be used byautomated change detection systems in workstations using down lookingaerial video. This can be done using a line scanning approach to thesequence of frames. In alternative image manipulation techniques, oncamera sensors such as inclinometers and digital compass information canalso be tagged to a specific frame and used to calculate the morphingparameters to more closely register before and current imagery.

As noted previously, there are various hardware options available inpracticing the present invention. For example, one could use a simplelow cost web cam to provide the necessary imagery. Traditional camerassuch as palmcorders with image stabilization could also be usedeffectively. Thermal imagery can be employed. Low light intensifiedcameras and low light video cameras can also be used as well as imagesproduced by magnetic imagery, radar, sonar and rendered images fromdepth maps can additionally be employed. If analog video signals are tobe employed (NTSC), a frame grabber card with onboard JPEG compressionis desirable. This is all capable of being implemented into a personalcomputer. Alternatively, a video to USB or analog to digital convertercan be employed for input sources. A Garmin® GPS device can be employedfor geo referencing including the GPS coordinates and time of day or aninertial GPS system could be used.

It is also considered an aspect of the present invention to provide, onan as needed basis, various indicators of potential hazards on the videoor appended audio archive. For example, voice commands, magneticsignatures, environmental sound, vehicle velocity, weather conditions,lighting and other environmental factors could be installed onto thememorialized depiction of a scene. On screen warnings of upcomingevents, checkpoints, or decision points could be triggered by GPSpositioning. In addition, vehicles can communicate with one anotherusing DVD and server laptop data links as well as file managementservers.

The software to be employed in practice in the invention must havecertain obvious requirements. It must be capable of processing a livecamera and sensor input while displaying output on a split screen.Although not required, the simultaneous recording and playbackcapability provides a system to automatically present the most recentdata. The software must be capable of receiving GPS input for currentvehicle positioning while selecting from a reference database of viewsthe one view designated by closest GPS coordinates. Although notrequired, the same GPS coordinates can be employed to shift X and Ycoordinates of the rendered view while displaying roadside changes,preferably in stereoscopic 3D based upon monoscopic 2D input signals.Better registration between the recorded and current image can beachieved using known techniques that consider the current camera egomotion and the acquired ego motion acquired from image interpolation oronboard sensors such as inclinometers, accelerometers or a digitalcompass. This onboard sensor information can be part of the meta-datafields embedded with each acquired image. This later feature isdesirable for in depth examination. Again, as noted previously, as apreferred embodiment, the software can also utilize existingsemi-automated change detection software to highlight on screensuspected hazards. The software code would utilize on board GPS devicesin real time culled from an appropriate database of the most closelystored video frame. The closest GPS view is selected from the databaseas the onboard camera simultaneously displays both images. The imagesare ideally expanded horizontally (or squeezed vertically) to make thenecessary X, Y adjustments based on road position and or onboard sensorswhile recording images from onboard cameras to a storage device forfuture reference. Morphing software can also be used to improve theregistration. It is also contemplated that the present invention willtrack the time and elevation that the video was captured and stored asthis information as part of the “meta tag” data set. An XML schema willprovide an interface for such information.

As noted previously, real time change detection software can be employedin conjunction with the present invention. Standard Geo Referenced Data(ARC Info/GIS) information can be imported and exported. In additionchange detection software can compliment the system. Use of suchsoftware can be of assistance to eliminate false positives thus makingthe present invention more viable to an untrained operator. Images canbe displayed to the operator on HMDs, heads down displays, LCDs,projection and laptop screens.

Rural and suburban areas can be mapped and “meta tagged” with a GPScoordinates and stored in an appropriate library. In the event of anatural disaster, such as an earthquake where roadway surfaces andsurrounding topography can be substantially altered and thus create ahazard, such alteration could be readily visualized through the use ofthe present invention.

Furthermore, a camera from a watercraft can be used to preciselynavigate a channel and avoid hazards. It can also be used to better landan aircraft in unfamiliar terrain or enter a port and make precise turnsin relation to visual objects such as buoys. Comparisons of objects suchas power lines, road markers and painted lines, roadside vegetation,tunnels and movement of terrain can also be made.

Use of this invention as a navigational aid during nighttime, or fordocumenting deliveries of equipment along a route can also be made. Forexample, a delivery route that includes the specific turns, dockapproach and an image of the delivered items on a dock may be ofspecific interest to train drivers and monitor and document driverperformance and serve as a proof of delivery. Precise positioning of avehicle can be made utilizing the comparison of the perfect positionpreviously recorded to the current position. For example determiningwhen to turn into a channel can be precisely made by matching shorelinetrees , docks, buoy positions previously recorded by an expert navigatorcan be compared to the current position. This same principal can be usedby large trucks trying to enter narrow loading docks.

1. A method of detecting a changed condition within a geographic spacefrom a moving or still vehicle comprising capturing and memorializingimages or sensor data of the geographic space in conjunction with GPS orotherwise acquired geographic coordinates associated with saidgeographic space, traversing said geographic space from said movingvehicle while accessing such coordinates, playing back said memorializedimages by coordinating geographic coordinate data on said memorializedimages with the traversing of said geographical space such that saidmemorialized images are views of the same geographical space beingtraversed, and presenting to an observer, for a comparison of thememorialized images to the geographical space being traversed.
 2. Themethod of claim 1 wherein said images are video images.
 3. The method ofclaim 1 wherein said memorialized images are captured from a camerapositioned upon said moving vehicle or moving camera/sensor platform. 4.The method of claim 3 wherein said images of said geographical spacebeing traversed are observed by viewing the output of a camerapositioned at substantially the same location on the moving vehicle asthe camera location used to capture said memorialized images.
 5. Themethod of claim 1 wherein said memorialized images and images viewed ofthe geographical spaced being traversed are simultaneously provided ontoone or more viewing screens.
 6. The method of claim 5 wherein a singleviewing screen provides split images separated by horizontally extendingline of demarcation.
 7. The method of claim 6 wherein the upper half orportion of said viewing screen provides images of the geographic spacebeing traversed and the lower half of said viewing screen providesimages of the memorialized images.
 8. The method of claim 1 wherein saidmemorialized images are taken at a time of day when said geographicspace is traversed.
 9. The method of claim 1 wherein said memorializedimages are taken at a substantially different time such as duringdaylight hours and said geographic space being traversed is traversed atnight or other time of day.
 10. The method of claim 9 wherein saidgeographic space being traversed is being traversed using an infraredcamera, intensified camera, or other raster based sensor such as sonar,ladar, or radar.
 11. The method of claim 1 wherein said geographic spacebeing traversed is being traversed using a line scan sensor or othersensor such as a magnetometer or audio sensor or other geo referenceddata producing sensor.
 12. The method of claim 1 wherein said geographicspace being traversed is being traversed using an 360 degree Field ofView camera
 13. The method of claim 1 wherein said geographic spacebeing traversed is being traversed using more than one sensor orcombinations of sensors.
 14. The method of claim 1 wherein saidmemorialized images are memorialized on a DVD, or other recordingmedium.
 15. The method of claim 1 wherein images or other data aretagged with meta data representing GPS location, view direction,elevation or time of day.
 16. The method of claim 1 wherein images orother data are tagged with meta data representing geographic locationfrom inertial sensors, inclinometers, accelerometers, digital compass,view direction, and time of day.
 17. The method of claim 5 whereindifferences between said memorialized images and the geographic spacebeing traversed are highlighted on said viewing screen.
 18. The methodof claim 5 wherein differences between said memorialized images and thegeographic space being traversed are highlighted on said viewing screenby rapidly alternating the display of the current and previous imagery.19. A method of reducing database requirements and bandwidthrequirements of a system capturing camera-based images from a movingvehicle or sensor platform by selectively recording imagery according tothe distance traveled by said moving vehicle or sensor platform.
 20. Themethod of reducing the database requirements and bandwidth requirementsof a system capturing camera-based images from a moving vehicle orsensor platform comprising using a GPS triggered camera that willproduced imagery according to the distance traveled by said movingvehicle or sensor platform.
 21. A method of providing a navigation viewto a vehicle operator within a geographic space including a navigationalview from a position behind said vehicle, said method comprisingmemorializing images of the geographic space behind the vehicle inconjunction with GPS or otherwise acquired geographic coordinatesassociated with said geographic space and playing back said memorializedimages of the same geographical space being traversed.
 22. A method ofdetermining the current position of a vehicle within a geographic spacecomprising memorializing images or sensor data of said geographic spacein coordination with GPS or otherwise acquired geographic coordinates ofsaid geographic space and comparing the GPS or otherwise acquiredgeographic coordinates so memorialized with geographic coordinates atsaid position of said vehicle.
 23. The method of claim 22 wherein asequence of frames are memorialized by GPS coordinates, and wherein theclosest one of said frames is compared with the GPS coordinates for thevehicle position at the time of comparison.
 24. A method of aiding inthe navigation of a moving vehicle over a selected geographic spacecomprising establishing a database of images or sensor data of saidgeographic space in conjunction with GPS or otherwise acquiredgeographic coordinates associated with said geographic space, traversingsaid geographic space from said moving vehicle while accessing suchcoordinates, and playing back said memorialized images by coordinatinggeographic coordinate data on said memorialized images while traversingsaid geographical space such that said memorialized images are viewed ofthe same geographical space being traversed.